Study of concentration dependent curcumin interaction with serum biomolecules using ATR-FTIR spectroscopy combined with Principal Component Analysis (PCA) and Partial Least Square Regression (PLS-R)

The binding of curcumin with biomolecules in biological fluids can affect the activity, distribution, rate of excretion, and toxicity of pharmaceutical agents in the body. It is said that interaction of curcumin with bio molecules such as protein can increase its bioavailability. A simpler alternative to current methods for study of curcumin interaction with biomolecules in biological fluids and the quantification of the interacted curcumin is therefore useful. Herein we demonstrated a method based on ATR-FTIR spectroscopy combined with multivariate analysis for concentration dependent curcumin interaction with serum biomolecules as a model. ATR-FTIR spectra of curcumin-spiked serum samples were acquired and data were processed with two different multivariate methods namely, Principal Component Analysis (PCA) and Partial Least-Squares Regression (PLS-R). PCA of the protein region (1701-1304 cm(-1)) shows a separation into groups based on the concentration of curcumin with no overlaps indicating the curcumin interaction is highest with serum proteins other than lipids and carbohydrates. PLS-R was employed to construct a calibration plot in carbohydrate, protein and lipid regions. The limit of detection of the interaction for all three regions was 10 ppm.